Shrouded rotors for compressors, turbines and the like



Dec. 5, 1961 E. A. STALKER SHROUDED ROTORS FOR COMPRESSORS, TURBINES AND THE LIKE Filed Nov. 19, 1956 1.111 Ill/71L 2 Sheets-Sheet 1 Dec. 5, 1961 E. A. STALKER 3,011,759

SHROUDED ROTORS FOR COMPRESSORS, TURBINES AND THE LIKE Filed Nov. 19, 1956 2 Sheets-Sheet 2 r r '1 ,"60 32 f 4 77 /54 g A w /a 42 Q M 4 44 IN V EN TOR.

United States Patent Ofihce Patented Dec. 5, 1961 3,911,759 SERGUDED R GTGRS FGR CGMPRESSORS, TURBINES AND THE LIKE Edward A. Stalker, 406 N. Farragut St., Bay City, Mich. Filed Nov. 19, 1956, Ser. No. 622,939 8 Claims. (Cl. 253-39) My invention relates to rotors with shrouds about the tips of the rotor blades.

An object of my invention is to provide a bladed rotor with a strong and light weight shroud.

Another object is to provide a shrouded rotor wherein the blades are disengageably secured in a hub means for relative radial movement for withdrawal of the blades from engagement with the shroud means.

Still another object is to provide a rotor with a peripherally continuous shroud secured on disengageable blades of a rotor.

Other objects will appear from the specification, appended claims and accompanying drawings.

The above objects are accomplished by the means illustrated in the accompanying drawings in which FIG. 1 is a rear view of a compressor rotor;

FIG. 2 is a fragmentary view of the hub rim on line 2-2 in FIG. 1;

FIG. 3 is a fragmentary section on line 33 in FIG. 1;

FIG. 4 is a fragmentary section of the rotor on line 44 in FIG. 2;

FIG. 5 is a fragmentary rear axial view of a rotor on on an enlarged scale with the blades withdrawn radially, according to this invention;

FIG. 6 is an enlarged fragmentary section on line 66 in FIG. 4;

FIG. 7 is a side view of a tip fragment of a blade;

FIG. 8 is a fragmentary radial view of a shroud means; and

FIG. 9 is a radial view of a fragment of a shroud means secured to the blades.

In my US. patent application Serial No. 458,912, filed September 28, 1954, I have disclosed a shroud means somewhat similar to the shroud means of the instant application. One difierence from the earlier one is that the subject invention provides for removable or disengageable blades as well as a peripherally continuous shroud.

For structural and aerodynamic reasons it is desirable to provide a shroud which is structurally continuous in a circle about the blades. This is difiicult to do while providing for removal of the blades from the rotor, as for replacement.

In the present invention the blades are each disengage able at their radially inner ends and the blade and hub structures are recessed one relative to the other for cooperation so that each blade can move radially inward a short distance whereby the tangs on the tip end of each blade can be withdrawn radially inward out of engagement with the shroud.

Referring now to the drawings a rotor for compressors, turbines and the like is indicated generally in FIGS. 1 and 3 as 18. It comprises the rotor hub means 12, the rim means 14, the blades 16 and the shroud means 18.

The hub means comprises means, such as the toothed ring shown, for engagement of the rotor to another rotor or to a driving means, and the disk.

As shown particularly in FIGS. 2 and 3 the rim means may comprise the annular disks 22 and 24, and the rim 26, each preferably a complete ring.

Each blade, FIGS. 3 and 4, has a stem means 3% comprising preferably a front part 32. and rear part 34. These are preferably channels placed back to back within the blade but spread apart at the disk 36 so that each fits into recesses of ribs 4%), 42, preferably of channel cross section Each stem part is disengageably connected preferably by bolts 44 to the legs of the channel rib. When the bolts are removed each stem and blade can he slid radially inward a short distance relative to the shroud and the hub means so that the tip 5% of each blade is free of the shroud, as shown in FIG. 5. The shroud can thus be removed by an axial movement and each or any blade can then be removed from the rotor.

The tip or" each blade has one or more tangs, preferably two 52 and 53 spaced chordwise, which are inserted in slots 54, FIGS. 7 and 8. These lie between the shroud flanges 56 and 5'8 and the radially extending legs of the shroud channel 60.

Each tang has a hole 62 through which a disengageable fastening means such as a pin 64 for instance is operable to position the shroud relative to the blade. A wire 65 encircling the shroud means is used through the holes 62 in the front tangs. Its ends may be joined by a turnbuckle 66. In some uses the fastening means may be omitted. Since the shroud is a continuous ring it is structurally self-sustaining in rotation like a hoop and the blade tips position the shroud centrally in the rotor but do not need to restrain it radially.

The shroud and rotor hub means are particularly adapted to sheet metal construction.

It will now be clear that I have provided a novel shroud means which forms a continuous ring about the tips of the blades and yet provides for disengagement of the blades and their removal from the rotor.

Shrouds are important to restrain the vibration of blades and increase their working life.

The shroud of this invention is capable of sustaining itself structurally as a hoop Without radial support from the blades. It may also be disengageably connected to the blades. In either case the blades and shroud bear on one another and reduce the tendency to vibrate.

While I have illustrated a specific form in this invention it is to be understood that I do not intend to limit myself to this exact form but intend to claim my invention broadly as indicated by the appended claims.

I claim:

1. In combination in a bladed rotor for compressors, turbines, and the like, a hub means having a disk and a rim secured thereto at the perimeter thereof, said rim extending between blades and from front to rear thereof, a plurality of hollow blades peripherally spaced about said rim extending radially outward thereof, a peripherally continuous shroud means encircling said blades at the tips thereof, each said blade having a stem means within with the tip end thereof directed through said shroud means and disengageably secured thereto, each said stem means passing through said rim radially inward thereof, disengageable means inwardly of said rim for removably securing each said stem means to said disk, and means providing for movement of said stem means in a radially inward direction to separate the tip ends of said blades from said shroud means.

2. The combination of clmm 1 wherein said shroud means has a peripherally continuous radially extending leg on the outward side thereof, and said stem means has spaced tanks at the tip end thereof passing through said shroud means axially aside from said leg to preserve its peripheral continuity. I

3. The combination of claim l wherein said stem means comprises front and rear parts spaced apart at their radially inner ends for receiving said disk therebetween with sufficient clearance at the edge of said disk to slide said parts radially inward to disengage said stem means from said shroud means.

4. in combination in a bladed rotor for compressors, turbines and the like, hub means 11 Wing a disk and a peripherally extending rim secured thereto, a plurality of blades peripherally spaced about said extending radially outward thereof, said rim extending etween blades from front to rear thereof, shroud means encircling said blades at the tip ends thereof, each said blade extending through sai and into interlitting engagement with said shroud means, means for disengageably supporting each said blade on said disk in an operative position, said hub means and said blades being recessed one relative to the other to provide for movement of said blades radially inward and out oi en agement wi h said shroud means releasing said shroud means for sliding movement axially away from said blades and providing for withdrawal of said blades radially outwardly from said hub means.

' 5. in combination in a bladed rotor for compressors, turbines and the like, hub means having a disk and a peripherally extending rim secured thereto, said disk having peripherally spaced axially projecting elements bonded to the side thereof, a plurality of blades peripherally spaced about said rim and extending radially outward thereof, said rim extendingbetween blades and from front to rear thereof, a peripherally continuous shroud means encircling said blades at the tip ends thereof, each said blade extending into interfitting engagement with said shroud means, means for disengageably securing each said blade to one of said elements to support the blades in an operative position, said hub means and said blades being recessed one relative to the other to provide for movement of said blades radially inward from said operative position releasing said shroud mean-s for axial movement away from said blades providing for withdrawal of said blades radially outward from said hub means.

6. In combination in a bladed rotor for compressors, turbines and the like, hub means including a generally radially extending disk, a plurality of blades peripherally spaced about said disk and extending radially outward thereof, shroud means encircling said blades at thetip ends thereof, said shroud means having a peripherally extending surface and a plurality of axially spaced radially xtending legs fixed to the outer periphery of said surface, each said blade extending into interfitting engagement with said shroud means adjacent said egs respectively, means for disengageably supportingeach said blade on disk,

said disk and said blades being recessed one relative to the other providing for radial movement of said blades inwar -ly away from said shroud means providing for axial removal of said shroud means from said blades.

7. in combination in a bladed rotor for compressors, turbines, and the like, hub means having a disk and a peripherally extending rim, a plurality of blades peripherally spaced about said and extending radially outward thereof, shroud means encircling said blades at the tip ends thereof, each said blade extending radially outward into contact with said shroud mean, said rirn extending between blades and from front to rear thereof, means for disengageably connecting each said blade to said disk radially inwardly of said rim, said hub means and said blades being shaped relative to each other to provide for radial movement of said blades inward from said shroud means and the axial removal of said shroud means from encircling relation with said blades.

8. In combination in a bladed rotor for compressors, turbines, and the like, a hub means having a rim, a plurality of blades peripherally spaced about said rim extending radially outward thereof, a shroud means encircling said blades at the tip ends thereof, said shroud means comprising a peripherally continuous ring and a plurality of axially spaced radially extending legs fixed to said ring on the outer surface thereof, each said blade extending into said shroud means alongside a said leg leaving said leg peripherally continuous as a circular ring about said blades, said blades extending t rough said rim, means for disengageably supporting each of said hub means inwardly of said rim, said blades being recessed to provide'for radial movement thereof inward away from said shroud means releasing said shroud means for axial movement away from said blades and pro for removal and replacement of said blades.

Reterences fitted in the file of this patent UNiTED STATES PATENTS 913,273 Emden Feb. 23, 1969 1,366,119 Darling Ian. 18, 1921 FOREIGN PATENTS I 365,815 France July 7, 1986 623,710 Great Britain May 20, 194-9 

